A plasma processing apparatus generates plasma, and makes ions in the plasma to be incident on a substrate (semiconductor wafer, for example), to thereby process the substrate, in a process of manufacturing a semiconductor device, when incident ions perform etching on a substrate, a trench, a via hole, a projecting portion and the like are formed.
Here, in the process of manufacturing the semiconductor device, it is important to perform fine control of processing shape, particularly vertical processing of a sidewall of trench for securing electrical performance of the semiconductor device. For example, a device with three-dimensional structure in recent years has a deep hole with large aspect ratio.
However, it is not always easy to perform the fine control of processing shape. For example, it is usually the case that the sidewall of trench is not vertically formed, and is tapered.